Pebble-mill.



No. 849,730. PATBNTED APR. 9, 1907. G. s. EMERIGK. PEBBLE MILL.

APPLIOATION FILED SEPT. 20,1906.

2 SHEBTS-SHEET 1.

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.lIflnrney UNITED STATES PATENT OFFICE.

PEBBLE-MILL.

Specification of Letters Patent.

Patented April 9, 1907.

Application filed September 20, 1906. Serial No. 335,503.

To all whom it may concern.-

Be it known that I, GEORGE S. Ennmcn, a citizen of the United States, residing at Nazareth, in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Pebble- Mills, of which the following is a specification.

My invention relates to that class of grinding or comminuting machinery wherein the material to be reduced is subjected to the ac tion of pebbles or balls within a rotating cylindrical casing and my object is to provide, first, an improved means for feeding such material to a mill of this character, and, secondly, to provide a means whereby the progress of the material from the feed end to the discharge-outlet may be suitably retarded in order thereby to increase the effective action of the pebbles or balls employed in grinding. I accomplish these objects by the means herein described, and shown in the accompanying drawings, in which Figure 1 is a view in elevation in vertical section of the entire mill exclusive of certain details of the feed mechanism; and Fig. 2 is a view in elevation in vertical section on the line X X, Fig. 1, and on an enlarged scale, of the details of the feed mechanism not shown in Fig. 1.

In Fig. 1 the cylindrical casing or body 1 is supported upon its feed-trunnion 2 and discharge-trunnion 3 and is adapted to be rotated in the usual manner by any suitable power appliances. (Not shown.) The interior of the casing 1 is provided with a series of what I term retarding-rings 4, 5, and 6, arranged transversely to the axis of the easmg, the diameters of the central openings of the rings decreasing progressively from the feed to the discharge end of the casing. To the feed end of the casing 1 are secured a plurality of annular plates 7 and S, the series terminating in the non-perforated plate 9, the annular plates and non-perforated plate being secured each to each and suitably spaced apart. One end of the worm-casing 10 is mounted in the feed-trunnion 2 by means of the packing-gland 11, and the worm 12 in said casing is rotated by means of the shaft 13 the squared end of which is carried by the non-perforated plate 9. Upon the wormcasing 10 is mounted the feed-chamber 14, which communicates therewith and which is furnished with the feed-roll 15. The feedpipe 16 communicates with the upper end of said feed-chamber. The feed-roll 15 is retated by means of the gears 17 and 18, the latter being mounted upon the outer end of the worm-shaft 13.

In Fig. 2 the communication of the feedpipe 16 with the feed-chamber 14 is controlled by any suitable mcans, such as the slide 19. The feedchamber is furnished with the tailing spout or outlet 20 and the inclined screen 21, the latter being of any suitable mesh and arranged to communicate with said outlet 20, the free edge of said screen being supported in such wise as to just clear the surface of the feed-roll 15.

The feed mechanism herein shown and described has a twofold object. In the initial feeding of material into the mill it sometimes happens that metal bolts or scraps of various kinds, together with other lumps of material, such as rock, pass in with the general mass and occasion damage by breakage of the worm or other parts of the feed mechanism, necessitating a consequent stoppage of the mill for repairs. By the employment of my inclined screen in connection with the feedroll all material of this character, together with any other masses of too great diameter to pass the mesh of the screen, is carried oil before it has an opportunity to reach the worm and be introduced into the mill. Furthermore, the output ol a mill of this class is increased by securing a certain grade or de gree of iincness in the material before it is subjected to the comminuting action of the pebbles or balls, and this result is also secured by the use of the screen, the mesh of which regulates, so to speak, the grade of the material at this preliminary stage. In the next place, it is essential that the final process of feeding to the pebbles in the interior of the casing shall take place near the inner periphery of the casing rather than at the axis thereof, inasmuch as the pebbles are thereby enabled to act more effectively in disintegration. To this end I employ a drum composed of annular plates and headed by a nonperlorated plate, the several plates of the drum being parallel each to each and suitably spaced apart. The material passing the screen 21 is carried by the worm to the inlet-trunnion and thence passes through the openings between the annular plates into the body of the mill.

It is a defect in mills of this class that the material to be reduced thereby passes too rapidly from the feed to the discharge end of the casing to enable the balls or pebbles employed to act with full effect. This difliculty I have obviated by the use of my retarding-rings, whereby the progress of the material from end to end is retarded, while at the same time the advantage of the undivided weight of the entire mass of pebbles is preserved.

While I have shown and described a certain number of annular rings as composing my feeddrum, I do not wish to be understood as confining myself to such number, and the same is true respecting my retardingrings.

What I claim as my invention, and desire to secure by Letters Patent, is

In combination in a pebble-mill, means for separating and feeding material into said mill, consisting of a feed-spout delivering upon a feed-roll, an inclined screen in close juxtaposition to the surface of said feed-roll, a tailing-spout, a worm-casing and a worm adapted to rotate therein, and means for reducing the material fed into said mill, said means including a plurality of transverse, annular flanges progressively increasing in depth from the feed to the discharge end of said mill, whereby the passage of material through said mill may be retarded, substantially as and for the purposes described.

In testimony whereof I hereto affix my signature in presence of two witnesses.

GEORGE S. EMERICK. Witnesses:

ALFRED DUERR, ALBERT J. IVIEYER. 

